1. Field of the Invention
The present invention relates to data storage devices, and in particular to FLASH memory control methods.
2. Description of the Related Art
Flash memory is a general non-volatile storage device that is electrically erased and programmed. A NAND Flash, for example, is primarily used in memory cards, USB flash devices, solid-state drives, and so on. In another application with a multi-chip package technique, a NAND FLASH chip and a controller chip are combined in one package as an embedded MultiMediaCard (eMMC).
Generally, the physical storage space of a FLASH memory (e.g. a NAND FLASH) comprises a plurality of blocks. To release a block as a spare block, the entire block has to be erased. However, a block is not always erasable. A block may be damaged if an erase operation is performed too many times. To prolong the lifetime of a FLASH memory, a wear leveling between the different blocks is an important issue in the FLASH memory, to narrow the gap between the erase counts of the different blocks.